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HomeMy WebLinkAboutGeotechnical Feasible Study®EnGEN ' CORPORATION GEOTECHNICAL FEASIBILITY STUDY PRIVATE BMX TRACK SIPKOI RESIDENCE 33239 Susan Grace Court, Temecula, California 92592 ' Lot 24 of Tract 26941 — Assessor's Parcel Number: 965-220-029 Project Number: M3903 -GFS May 25, 2010 Prepared for: ' Rick & Cathy Sipkoi 33239 Susan Grace Court ' Temecula, CA 92592 ' 25759 Jefferson Avenue, Murrieta, California 92562 • Phone: (951) 834-9000 • Fax' (951)8349001 TABLE OF CONTENTS Section Number and Title Page 1.0 Site Suitability.................................................................................................................1 1.1 Structures..................................................................................................................1 1.2 Other Site Conditions...............................................................................................1 2.0 Site Review & Geotechnical Investigation..............................................................2 3.0 Earthwork Recommendations..................................................................................2 3.1 General......................................................................................................................2 3.2 Clearing......................................................................................................................2 3.3 Excavation Characteristics......................................................................................2 3.4 Suitability of On -Site Materials as Fill..................................................................... 2 3.5 Grading Recommendations for All Areas................................................................3 3.6 Structural Fill.............................................................................................................3 3.7 Compaction Equipment............................................................................................4 3.8 Shrinkage — Alluvium&Colluvium..........................................................................4 3.9 Keyways.....................................................................................................................4 4.0 Observation and Testing..........................................................................................4 5.0 Stability Evaluation of Cut and Fill Slopes..............................................................5 6.0 Finish Lot Drainage Recommendations..................................................................5 7.0 Supplemental Construction Observations and Testing.........................................5 8.0 Plan Review...............................................................................................................5 9.0 Closure.......................................................................................................................6 ®EnGEN CORPORATION IMay 25, 2010 Mr. & Mrs. Rick Sipkoi 33239 Susan Grace Court Temecula, CA 92592 ' (949) 533-5515 Regarding: GEOTECHNICAL FEASIBILITY REPORT ' Private BMX Track 33239 Susan Grace Court, Temecula, California 92592 Lot 24 of Tract 26941 — Assessor's Parcel Number: 965-220-029 ' Project Number: M3903 -GFS Dear Mr. & Mrs. Sipkoi: In accordance with your request, a representative of this firm has performed a geotechnical field reconnaissance of the subject site to visually observe the surficial conditions and provide an opinion of the need for a Subsurface Geotechnical Study for the proposed grading to create a private track for BMX bicycle practicing. Submitted herewith are the results of our findings along with recommendations for grading. ' 1.0 Site Suitability: The site is part of a 3.69 -acre (net) residential parcel with a naturally contoured backyard well suited for the proposed creation of a practice track with very ' minimal grading. The proposed grading is feasible from a geotechnical standpoint provided the recommendations contained herein are incorporated into the final design and ' construction of the project. 1.1 Structures: No structures are proposed for this phase of site development. An existing ' single family residence presently occupies the site, and is not to be altered in any fashion as part of this development effort. As a result, no recommendations are necessary with respect to structural design or construction. The proposed grading will not provide support for structures of any kind. ' 1.2 Other Site Conditions: The area proposed for grading is presently a residential yard covered with weeds of various kinds and some typical residential -type trees. The surface ' slopes towards the south and southeast, creating a contoured "bowl' very 25759 Jefferson Avenue, Murrieta, California 92562 • Phone: (951) 8349000 • fax: (951)8349001 Mr. & Mrs. Rick Sipkoi Project Number: M3903 -GFS May 2010 Page 2 conducive to a track layout. Maximum relief within the proposed track area is on the order of 60 feet in a distance of 300 feet. No structures are located in the area to be graded. Access to the track will be via the existing residential driveway. 2.0 Site Review & Geotechnical Investigation: Based on our field reconnaissance, it appears that a mantle of residual soils, colluvium and alluvium mantles the older Pauba Formation bedrock. The soils exposed at the surface are mostly silty to clayey sands and considered suitable for the proposed grading. Since no structures are proposed and only minor grading, with small slopes (5' +/- max.), mostly at inclinations of 3:1 and shallower are planned, it is our opinion that a subsurface investigation is not warranted and would be a waste of the owners resources. It is also considered of no practical value to include a regional geology dissortation together with possible seismic effects and design considerations. As a result, this letter is essentially limited to providing recommendations for the proposed earthwork, with the consideration that the area being developed is to be used for a bicycle riding track, and that the potential geotechnical effects on neighboring properties is nil. 3.0 Earthwork Recommendations 3.1 General: The grading recommendations presented in this report are intended for: 1) the use of a bicycle riding track; and 2) the re -compaction of near -surface earth materials to create earthen mounds to act as jumps within the track layout. The following recommendations may need to be modified and/or supplemented during rough grading as field conditions require. 3.2 Clearing: All roots, grasses, weeds, brush, trees and other deleterious materials should be removed from the proposed grading areas before grading is performed. No discing or mixing of organic material into the soils should be performed. Man-made objects encountered should be overexcavated and removed from the work area. 3.3 Excavation Characteristics: Excavation and trenching within the colluvium and alluvium is anticipated to be relatively easy. 3.4 Suitability of On -Site Materials as Fill: In general, the on-site earth materials expected to be encountered are considered suitable to be used as fill. Fill materials should be free ' Mr. & Mrs. Rick Sipkoi Project Number: M3903 -GFS May 2010 ' Page 3 of significant amounts of organic materials and/or debris. Fill materials should not contain rocks greater than 6 -inches in maximum dimension. The following recommendations are general in nature and are provided as guidelines only. Actual grading operations should ' be under the observation and testing of the geotechnical consultant of record to insure compliance with the recommendations of this Geotechnical Feasibility Report. t3.5 Grading Recommendations for All Areas: 1. All vegetation, including roots, should be removed from areas to be graded and not ' used in fills. ' 2. All encountered man-made materials such as irrigation piping, electrical conduits and associated materials should be excavated and removed from the project area and not used in fills. ' 3. All colluvium, alluvium and weathered bedrock in areas to receive fill shall be scarified to a minimum depth 6 inches, moisture conditioned and recompacted prior ' to placement of compacted fill. 4. No recompaction of cut areas is considered necessary. ' 5. No density testing of cut areas is considered necessary. 6. All fill placed on areas prepared in accordance with #3 above, shall be compacted to a minimum of 90 percent relative compaction. Maximum dry density and optimum ' moisture content for compacted materials should be determined according to ASTM D 1557-02 procedures. ' 7. All fill slopes which are part of the mounds created for jumps shall be constructed at slope ratios of 2:1 (horizontal:vertical). All cut and fill slopes along the sides of the ' track shall be constructed at slope ratios of 3:1 (horizontal: vertical), or shallower. 3.6 Structural Fill: All fill material, whether on-site material or import, should be accepted by the Project Geotechnical Engineer and/or his representative before placement. All fill should be free from vegetation, organic material, and other debris. No imported fill is anticipated for this project. Approved fill material should be placed in horizontal lifts not exceeding 6.0 to 8.0 -inches in thickness, and watered or aerated to obtain near -optimum moisture content (within 2.0 percent of optimum). Each lift should be spread evenly and should be thoroughly mixed to ensure uniformity of soil moisture. Structural fill should ' Mr. & Mrs. Rick Sipkoi Project Number: M3903 -GFS May 2010 Page 4 meet a minimum relative compaction of 90 percent of maximum dry density based upon ASTM 1557-02 procedures. Moisture content of fill materials should not vary more than 2.0 percent of optimum, unless approved by the Project Geotechnical Engineer. ' 3.7 Compaction Equipment: It is anticipated that fill compaction for the project will be achieved by the use of a combination of rubber -tired and track -mounted heavy construction equipment. Compaction by rubber -tired or track -mounted equipment, by itself, may not be sufficient. Adequate hoses or water trucks should be available to ' provide sufficient moisture and dust control. The actual selection of equipment is the responsibility of the contractor performing the work and should be such that uniform and ' proper compaction of the fill is achieved. 3.8 Shrinkage — Alluvium & Colluvium: There will be a material loss due to the clearing and ' grubbing operations. Shrinkage of alluvial and colluvial materials that are excavated and replaced as compacted fill should be anticipated. It is estimated that the average ' shrinkage of these soils will be on the order of 15 percent, based on fill volumes when compacted to a minimum of 90 percent relative compaction. A higher relative compaction ' would mean a larger shrinkage value. 3.9 Keyways: No keyways are required at the toe of fill slopes due to the nature of the ' project and the small slopes being created. Typical benching, resulting in fills being placed on level grades is considered sufficient. 4.0 Observation and Testing: During grading, observation and testing should be conducted by the Project Geotechnical Engineer and/or his representative to verify that the grading is being performed according to the recommendations presented in this report. The Project Geotechnical Engineer and/or his representative should observe the scarification and the placement of fill and should take tests to verify the moisture content, density, uniformity and degree of compaction obtained. Where testing demonstrates insufficient density, ' additional compaction effort, with the adjustment of the moisture content where necessary, should be applied until retesting shows that satisfactory relative compaction has been ' obtained. The results of observations and testing services should be presented in a formal finish grading report following completion of the grading operations. The presence of the ' Project Geotechnical Engineer and/or his representative will be for the purpose of providing observations and field testing and will not include any supervision or directing of Mr. & Mrs. Rick Sipkoi Project Number: M3903 -GFS May 2010 Page 5 the actual work of the contractor or the contractor's employees or agents. Neither the presence and/or the non -presence of the Project Geotechnical Engineer and/or his field representative nor the field observations and testing shall excuse the contractor in any way for defects discovered in the contractor's work. 5.0 Stability Evaluation of Cut and Fill Slopes: No proposed manufactured slopes are large enough or steep enough to warrant slope stability evaluation. All fill and cut slopes are to be constructed in substantial accordance with the plans, at slope ratios of 2:1 or 3:1 (horizontal to vertical) to heights of approximately 5 feet maximum. It is our opinion that properly constructed cut and fill slopes at this inclination will possess gross and surficial stability in excess of generally accepted minimum engineering criteria (Factor of Safety at least 1.5) and will be suitable for their intended purpose. 6.0 Finish Lot Drainage Recommendations: The track surface is planned to provide cross - slope surface gradients of 1%, or more, and will distribute normal drainage to flow over the tops of the 3:1 slopes. Concentrations of surface water should be directed toward suitable drainage facilities or energy dissipating devices. Ponding of surface water should not be allowed other than at designed erosion control devices. Drainage off the property should be provided in a non-erosive manner. 7.0 Supplemental Construction Observations and Testing: Any subsequent grading for development of the subject property should be performed under engineering observation and testing performed by EnGEN Corporation. Subsequent grading includes, but is not limited to, any additional overexcavation of cut and/or cut/fill transitions, fill placement, and excavation of temporary and permanent cut and fill slopes. If any of the observations and testing to verify site geotechnical conditions is not performed by EnGEN Corporation, liability for the safety and performance of the development is limited to the actual portions of the project observed and/or tested by EnGEN Corporation. 8.0 Plan Review: Any changes to the project design as represented in this report, and any grading plans for the proposed development should be provided for review by this office to verify compatibility with site geotechnical conditions and conformance with the recommendations contained in this report. If EnGEN Corporation is not accorded the opportunity to make the recommended review, we will assume no responsibility for misinterpretation of the recommendations presented in this report. ' Mr. & Mrs. Rick Sipkoi Project Number: M3903 -GFS May 2010 Page 6 9.0 Closure This report has been prepared for use by the parties or project named or described in this document. It may or may not contain sufficient information for other parties or purposes. tIn the event that changes in the assumed nature, design, or location of the proposed project as described in this report are planned, the conclusions and recommendations contained in this report will not be considered valid unless the changes are reviewed and the conclusions and recommendations of this report are modified or verified in writing. ' This study was conducted in general accordance with the applicable standards of our profession and the accepted geotechnical engineering principles and practices at the time this report was prepared. No other warranty, implied or expressed beyond the representations of this report, is made. Although reasonable effort has been made to ' obtain information regarding the geotechnical and subsurface conditions of the site, limitations exist with respect to the knowledge of unknown regional or localized off-site ' conditions that may have an impact at the site. The recommendations presented in this report are valid as of the date of the report. However, changes in the conditions of a ' property can occur with the passage of time, whether they are due to natural processes or to the works of man on this and/or adjacent properties. If conditions are observed or information becomes available during the design and construction process that are not ' reflected in this report, EnGEN Corporation should be notified so that supplemental evaluations can be performed and the conclusions and recommendations presented in ' this report can be modified or verified in writing. Changes in applicable or appropriate standards of care or practice occur, whether they result from legislation or the broadening of knowledge and experience. Accordingly, the conclusions and recommendations presented in this report may be invalidated, wholly or in part, by changes outside of the ' control of EnGEN Corporation which occur in the future. Mr. & Mrs. Rick Sipkoi Project Number: M3903 -GFS May 2010 Page 7 Thank you for the opportunity to provide our services. If we can be of further service or should you have questions regarding this report, please do not hesitate to contact this office at your convenience. Because of our involvement in the project to date, we would be pleased to discuss engineering testing and observation services during construction operations that may be applicable on the project. Respectfully submitted, EnGEN Corporation a fEESS/n.. b-s'6jdrriB tene, dE 16-2— No.16 Irl PresideP•L Expires 09-30-11 �' v Jl �CTECVHA �Q OB:al 9TFQF CAUF��� Distribution: (2) Addressee (1) City of Temecula FILE: EnGEN\ReporbnglGFSV3903-GFS Sipkoi BMX Track Mr. & Mrs. Rick Sipkoi Project Number: M3903 -GFS May 2010 Page 8 DRAWINGS s ONE COMPLETE JUMP ONE COMPLI 30' so 20' so 30' MOUND SEPARATION TAKE– BETWEEN JUMPS MOUND SEPARATION TAKE– MOUND 'r+ PaE' ZONE ZFF ONE O ZONE 4' TO 5' TYP. pIRECTION OF TRAVEL (VARIES) TYPICAL SECTION THROUGH JUMPS NTS FOR 5' JUMPS) • WIDTH e�-. =_ � t v '/ IV-. TYPICAL SMP AT UPPER SECTION .� NTS %Op ' 20'(TYP. FOR 5' JUMPS) WIDTH A! T OF JUMIF' TVDIrAl II IKAP AT I nwFR cFrTInNC TYPICAL SANDBAGS (2 HIGH) TYPIrAI I-,ANIf1R0(, nFTAII SILT nFICE-WOVEN FLIER FABRIC MATERIAL (SEIMW TO STAKE WH 4 STAPLES) It ■ Y NOW SUIS (OR EOIMN ENT) e -a' = WX SPACM sACIOU. NO COIPACr THE DWAVAIEO salt IN TRENCH AND ON BOM SM OF FLIER FABRIC FLOW ,� DISRMED O M M N47'39'48"W 10.79' am, FOR ENO STARE, FENCE FANK SWILL E FOLDED AROUND TWO STAKES ONE FIEI TURN AND SEMM WEN FOUR TYPICAL SILT FENCE Jer roux F rvice Aler ENGINEERS NOTE, C3 lIA PRWAII I_NGINEER SIGNING THESE PLANS IS k[' fP �NSIPI 1 I OR ASSURING THE ACCURACY OF DESIGN CALL TOLL FREE AND ACC( F,IAHILITY OF THE WORK HEREON. IN THE EVEN f 01 111` ,r_;REPANCIES ARISING AFTER COUNTY M-227 -2600 APPP,0VA1- t4,' DURING CONSTRUCTION, THE PRIVATE LNGINI.FR `1 MI BE RESPONSIBLE FOR DETERMINING AN A(.(.[ PlAiii L SOLATION AND REVISING THE PLANS FOR APPRCVAI BY THE CITY. TWO WORKING DAYS BEFORE YOU DIG It NOTE: NO INTERCEPTOR DRAIN H/5 2' MIN REQUIRED FOR SLOPES 3:1 OR FLATTER 10' MAX REQb INTERCEPTOR DRAIN 12" MIN 2 (MIN.) �1 NATURAL GRADE FINISH GRADE - TYPICAL BROW DITCH/SETBACKS NTS X86"20'44" R=48.00' L=72.34' iV69. '_US= -GRACE COURr j N87'33'3_0"W F- ----7 10 ---------- .80' 68' 52' 47" R=48.00' L= 57.7 1 ' TYPICAL EARTHEN V—DRAIN DETAIL NTS L0 1" 30' r I;i:izm 2 -� 1 BOTTOM GRAPHIC SCALE 60 90 120 Civil Engineers - RCE 11873 General Conductors -Lim 378242 BRATEIVE 25759JefeaonAve. CON S TRUCHON & Murrieta, CA 92562 _,GNGMERING (951)834-9009 (951) 834-9007 (FAV���' DATE BY REVISIONS DATE ACC'DI SCALE DESIGNED BY DRAWN BY CHECKED BY RECOMMENDED BY: DATE: ACCEPTED BY: ENGN� & DIRIIXTDR OF S`Qmb GREG BUTLER R.C.E. No, 47109 CITY 0 F T E M E C U LA DEPARTMENT OF PUBLIC WORKS Drawl "� No. OB DB OB G-2 HORIZONTAL Plans Pr"mrsd Under The Supervision Of Date: OSBJORN BRATENE R.C.E. No. 21873 PRECISE GRADING PLAN SIPKOI BMX TRACK 33239 SUSAN GRACE COURT TEMECULA, CA 1"=30' N/A SHEET 2 of 2 r`\n \�� ■rr ."w n"InllG\M"""h _- rnNi , xnunYMa w . n WIIX03 IA -n